Syngenta released MIR162, trade name Agrisure Vipera, in 2009. It is engineered to make a Bacillus thuringiensis (Bt) protein vip3Aa20 toxic to lepidopteran insect pests (butterflies and moths) [Event Name: MIR162, International Service for the Acquisition of Agri-Biotech Applications, accessed 13 October 2014, http://www.isaaa.org/gmapprovaldatabase/event/default.asp? EventID=130], and also has a gene pmi (phosphomannose isomerase) from E. coli to allow positive selection for the transgene.

It was created with Agrobacterium tumefaciens-mediated plant transformation, a particularly hazardous vector system that risks further horizontal gene transfer (see ‘Ban GMOs Now', ISIS Special Report available at http://www.i-sis.org.uk/Ban_GMOs_Now.php).

While MIR162 is approved for use in the US, China has not allowed its import into the country.

Syngenta is blamed for destroying the export of US corn to China, which led to depressed prices for domestic corn, according to Volnek Farms, the lead plaintiff in the lawsuit filed in Omaha, Nebraska federal court. The two other suits were filed in Iowa and Illinois federal courts.

None of the farmers involved in the lawsuits planted MIR162 seed in their fields in Illinois, Iowa, Kansas, Missouri, and Nebraska. But their harvested crop was contaminated with traces of the transgenic trait, and hence unsalable to the Chinese market.

Although Viptera has been planted on only about 3% of US farm acreage, it is difficult to say for sure "that any shipments of US corn will not be contaminated with trace amounts of MIR162", the Nebraska plaintiff stated.

The National Grain and Feed Association (NGFA) had encouraged Syngenta to stop selling Viptera, according to the Iowa claim. The NGFA estimated that actions taken in China against US corn have caused prices to drop by 11 cents per bushel.

The Iowa suit also claims that the release of Syngenta's Viptera caused the US-to-China export market to drop by 85%. Nebraska plaintiffs, too, accuse Syngenta of having crippled the 2013-14 corn export market to China.

The NGFA reported in April 2014 that China had barred nearly 1.45 million tons of corn shipments since 2013.

In 2011, Syngenta requested in federal court that a grain elevator firm, Bunge North America, to remove its signs that said it would not accept Vipera corn. The request was denied.

Concern over the safety of GM food may have played a role in a recent decision by China's officials to move away from GM production.

[* Dr Mae-Wan Ho is the co-founder and director of the Institute of Science in Society (ISIS), an independent, not-for-profit organisation founded in 1999 and dedicated to providing critical public information on cutting-edge science, and to promoting social accountability and ecological sustainability in science. Since 1994, she has been scientific advisor to the Third World Network. This article was first published on the ISIS website and can be found at: http://www.i-sis.org.uk/Syngenta_Sued_for_$1_billion.php] +